The preferred embodiments relate to magnetometers and, more particularly, to a Zeeman splitting vector magnetometer apparatus and method.
Magnetometers measure magnetic fields and are used in numerous fields and endeavors, including scientific experiments and observation, medical systems, and military applications. Atomic magnetometers are highly sensitive and thereby permit the measure of magnetic forces that are extremely small, even relative to the earth's magnetic field. However, such devices typically involve plural lasers and often measure only magnetic field strength (i.e., scalar) or direction, whereas to determine both strength and direction as a complete vector, complicated or duplicative apparatus may be required.
By way of further background, the prior art includes various approaches to an atomic magnetometer that use a vapor cell in which heated atoms of an alkali metal (e.g., cesium or rubidium) are suspended via a buffer gas, and two lasers are oriented to emit photons in perpendicular paths relative to one another through the cell. A first laser is considered a pumping laser, in that it pumps photons into the alkali atoms so as to polarize the atoms by populating spin states, and then the second (and lower-powered) laser is considered a probe laser in that it measures the frequency of the spin precession of the polarized atoms, also known as the Larmor frequency, so as to determine a amplitude of magnetic field which is proportional to the measured Larmor frequency. As indicated above, however, such an approach measures only the magnetic field scalar amplitude, and not direction. To get a full magnetic vector (i.e., amplitude and direction), such an approach can be packaged with three different magnetometers, each oriented in a plane orthogonal to the others, but with the added cost and complexities of such an approach.
Thus, while the prior art approaches have served various needs, the present inventors seek to improve upon the prior art, as further detailed below.